Apparatus for molding concrete building segments



Jan. 15, 1952 A. HENDERSON APPARATUS FOR MOLDING CONCRETE BUILDINGSEGMENTS Filed NOV. 2, 1950 INVENTOR.

Mzdmm application.

Patented Jan. 15, 1952 APPARATUS MOLDING CONCRETE BUILDING SEGMENTSAlbert Henderson, rittsburgnra. Application November 2, 1950, Serial No.193,587

This invention has for its object the providing of an app-aratus formaking long span precast reinforced concrete building segments, fullyshown and described in the above co-pending Another object of thisinvention is to provide apparatus for making long span reinforcedconcrete building slabs having spaced, deep, Astraight or tapered iiangemembers integrally cast thereto.

I Aovercome a bad feature of casting the segments in situ and that is inhigh concrete walls a scum or laitance forms on the top of the concreteand is diflicult to remove due to the vertical reinforcing rods embeddedin the wall concrete and which extend into the wall member. When I castthe segments on their edges I can easily remove any scum which mightarise in the relatively small width of the segment which is generallyonly 5 feet. When I screed the top of the concrete in my apparatus thereis no obstruction to the removal of any scum.

My apparatus permits, furthermore, the equal and exact density of theconcrete in each framing member or ange of the segment. This equaldensity Vof concrete in the iianges is vitally important for if theconcrete has not equal density then the big segment, sometimes weighingtons, will warp sideways and the segment would not evenly abut theadjacent segment. In fact it could be .so bad that the segment wouldhave to be scrapped. To prevent undue warping in a concrete segment itis imperative that the con crete be of the same density throughout sothat it can shrink evenly. I therefore cast each flange of the segmentindependently of each other and no fluid concrete other than theconcrete in each iiange is allowed to exert pressure on the uid concretein the flanges.

Another object of this invention is to provide an apparatus which caneasily make long span concrete building segments having tapered framingmembers or flanges. Furthermore, this apparatus provides a simple methodof installing cores for making openings in the anges to cut down thedead weight of the iianges. The flange then becomes an open truss. Toobtain open truss effects in spaced flanges of a concrete segment isvery diiiicult and costly and it has become the practice to make theflanges or framing members solid as it is cheaper to use the concreteinstead of trying to form openings, which openings Vary with the span ofthe segment. It becomes an easy matter to set the c ores required tosave concrete in my apparatus as the top sides of the molds for makingthe spaced flanges are open so that not only is the coring of theflanges made cheaply but I also can cast the lower flange of the segmentindependent of the slab and the upper flange.- Thus I get equal densityof theconcrete. Furthermore, casting the segments and flanges on theirsides makes simple the problem of giving the bottom of the ilanges atapered design. The tapered designed iianges also saves concrete andreduces the dead weight of the segf paratus is not necessary. Theapparatus is angle shaped along its longitudinal length so that anentire segment including the wall member and the roof member can be castin one simultaneous.

casting operation. The drawing shows the two main mold walls forming theapparatus. Mold Wall a rests on preferablythe building field castconcrete floor b. The inner form wall c is supported by members d.

Resting on both mold walls a and c are ange bottom mold walls e whichare braced by struts f. In the assembly of mold form walls a, c and e isshown a section of one of the concrete segments g.

Flange bottom mold walls e can be easily moved laterally to providetapered bottoms for the framing members or flanges.

In assembling the mold member c I rest its tapered bottom 'c1 on anytemporary supporting brick or small block such as Ca, then when theconcrete of the segment has hardened, I remove the supporting member dand lower the upper right corner of mold wall c and remove it. This iswhy I taper at c1 the bottom left side of mold member c. Thisfacilitates the removal of the mold member c. Then I remove hardenedsegment y. While I show the main walls of my apparatus to be made ofconcrete I may make them of metal or Wood.

While I show iiange bottom wall members e as an angle, I may make this a'channel having perforated anges. I may place the inner mold wall c onwheels and roll it away quickly and re assemble it quickly.

Although I have illustrated and described but a preferred embodiment ofthe invention, it will be recognized that changes in the details thereofmay be made without departing from the spirit of the invention or thescope of the appended claims.

I claim:

1. An apparatus for molding concrete building segments having spacedange members, comprising an upper open top flange mold and a lower opentop flange mold, a' laterally slidable mold wall for molding the bottomof said iiange members being disposed on each of said flange molds.

2. An apparatus for molding concretefbuildingv segments having spacedange members; com`-Y prising two monolithic precast reinforced concretemold Walls, each of said mold walls having a vertical member and ahorizontal member, af slidable mold wall for molding the bottom of eachof said iiange members being supported: orr theY horizontal member ofeach of said concrete mold walls.

3. A mold for molding concretefbuildingrsegments comprising anexterior'moldun'it having a bottom wall and a; side wall, an interior.mold unit having a side wall anda top wall, the' mold units beingarranged. with the side wall of' the' interior mold unit spaced inwardlyfrom the side wall ofthe exterior mold unit and spacedY above the bottomwall, and sildablemoldsv on the top' wall and the bottom wallrespectively.

4. A mold for molding concrete building segments, each having a web andspaced anges comprising an exterior mold unit having a bottom wall and aside wall, an interior mold unit having a, side wall and a top wall, themold units being arranged with the side wall of the interior mold unitspaced inwardly from the side wal] of the exterior mold unit and spacedabove the bottom wall, mold walls on the top wall and the bottom wallrespectively for molding the bottoms of said iianges.

5. A mold for molding concrete building segments, each having a web andspaced flanges, comprising an exterior side Wall and a bottom wail, aninterior mold unit having a side wall and a top Wall, the side wall ofthe interior unit being spaced inwardly from the exterior side wall and:being spacedA above the bottom Wall, and molds# for molding the bottomsof said iianges resting on the top wall and the bottom wallrespectively.

ALBERT HENDERSON.

REFERENCES CITED The following references are of record in the le of.`this.. patent:

UNITED STATES PA'IENTS

